I have 3 Tables: NotHeard,analyzed,analyzed2. In each of these tables I have two columns named UnitID and Address.

What I'm trying to do right now is to select all of the records for the columns UnitID and Address from NotHeard that don't appear in either analyzed or analyzed2. The SQL statement I created was as follows:

SELECT UnitID, Address  
INTO [NotHeardByEither] 
FROM [NotHeard] 
Where NOT EXISTS( Select analyzed.UnitID FROM analyzed WHERE [NotHeard].UnitID = analyzed.UnitID) 
or NOT EXISTS( Select analyzed2.UnitID FROM analyzed2 WHERE [NotHeard].UnitID = analyzed2.UnitID) 
Group BY UnitID, Address 

I thought this would work since I've used the single NOT EXISTS subquery line and it has worked just fine for me in the past. The above query however returns the same data that is in the NotHeard table whereas if I take out the or NOT EXISTS part it works correctly.

Any ideas as to what I'm doing wrong or how to do what I'm wanting to do?